A hard-throwing righthander out of the Dominican Republic, Gustave spent six seasons in the Astros' minor league system before making his big league debut in 2016 at the age of 23. Working out of the Astros bullpen 20 times over two seasons, he posted a 1-0 record and 3.98 ERA before injuries struck and he was released.

Gustave resurfaced again in 2019 with the Giants, compiling a 2.96 ERA and one save in 23 appearances.